Draftsman&#39;s triangle



ct. 5, 1954 F. TlscH 2,690,619

DRAFTSMANS TRIANGLE Filed Jan. ll, 1952 Patentecl Uct. 5.,

STATES ENT OFFICE l Claim.

The present instrument relates to an instrument for drafting, and more particularly it relates to a draftsmans triangle.

It is an object of the present invention to provide a draftsmans triangle the inner edges of which have a series of irregular steps or notches which serve as predetermined measuring guides.

It is a further object of the present invention to provide a draftsmans triangle which has preetermined scales and graduations on both front and rear faces thereby adapting the triangle for both right and left hand calculations.

Moreover, it is an object of the present invention to provide a linear rule on one of the outer edges of the triangle, which rule permits computation on either side of a center line.

In addition, it is an object of the present invention to provide a triangle having a series of lines or graduations parallel to the hypotenuse for aid in cross-sectioning a drawing.

Still further, it is an object of the present invention to provide a. triangle having edges which are unbevelled near the corners of the triangle so that the triangle will repose in a stable manner upon the drawing board.

Other objects and advantages of the present invention will become apparent as it is described in detail below with particular reference to the accompanying drawings, wherein Fig. 1 is a view of the front face of the triangle embodying the present invention;

Fig. 2 is a view of the rear face of the triangle; and,

Fig. 3 is a cross-section taken on the line 3-3 of Fig. 1, and looking in the direction of the arrows.

With particular reference to Fig. 1, there is shown a transparent or translucent draitsmans triangle II which is known as the thirty, sixty degree type. The triangle II has edges I2, I3 and I4 which are partially bevelled at surfaces I5, IB and I'I, respectively. The bevelled surface I5 is located on the top face of the triangle I I, whereas the bevelled surfaces I6 and II are located on the rear face. These bevelled surfaces do not extend quite to the junctions where the edges intersect with each other so that the corner portions of the triangle II have at top and under surfaces. This permits the triangle II to rest flatly upon the drawing board at all times, regardless of which face is in up position, and prevents any slight tilting or vibration due to pressure of the draftsmans hand as he holds the triangle in place.

Upon the bevelled surface I there is imprinted or otherwise marked a linear rule I8. The center of this rule is marked by the numeral 0. Extending both upwardly and downwardly from the 0 mark, the rule I8 has linear graduations from the numerals 1 through 5. Since there are graduations reading both upwardly and downwardly from the 0 mark, it is possible for the draftsman to make rapid measurements on either side of a center line with a minimum movement of the triangle Il.

Although, as shown, there are no further linear rules or indicia upon the other bevelled surfaces I5 and I1, such measuring guides may be marked or imprinted thereupon, if desired.

Through the body of the triangle I I there is an opening 30 dened by inner edges I9, 20 and 2l. These inner edges I9, 20 and 2| of the triangle II each comprises a series of irregular notches or steps SI. On any edge, each step SI is at a diiTerent and predetermined parallel distance from an adjacent step. Moreover, the length of each step differs from that of an adjacent step. Thus, the series of irregular steps on any one edge comprises a handy rule for the draftsman when a numeral guide is placed adjacent thereto as shown in Fig. 1. The iirst column of numerals of the guide indicates the length of each step and the second column of numerals indicates its distance from the next adjacent step. For example, if the draftsman wishes to measure a vertical line I- long, he employs the step so marked as shown in Fig. l. If he wishes to measure a horizontal distance of 3-32, he employs the horizontal surface just below the -le' step.

The inner edges 20 and 2l also have appropriate guide rules, as shown in Fig. 2, indicating the length and distance of each step. However, these guide rules appear on the rear face of the triangle` II. Thus when the triangle is in the right hand position, as in Fig. l, one set of guide indicia can be read. When the triangle is in the left hand position, as in Fig. 2, the remaining indicia of edges 20 and 2| can be easily read.

Parallel to hypotenuse edge I4 and on the rear face of the triangle II are a series oi separate markings 22. These markings 22 are at various distances from the hypotenuse edge Id. Adjacent each marking is a numeral designating the distance of the marking from the edge. The purpose of these markings '22 is to permit the draftsman to cross-section a drawing or obtain accurate spacing of parallel lines. For example, if he wishes to measure parallel spacing of a distance of one-quarter of an inch, he aligns the particular graduation indicated at one-quarter of an inch over the reference line of the drawing and then draws a parallel line at the edge I4 of the triangle Il.

While the invention has been described in detail and shown with respect to the accompanying drawings, it is not to be limited to such details, since many changes and modications may be made in the invention without departing from the spirit and scope thereof. Hence, it is desired to cover any and all forms and modications of the invention which may come Within the language and scope of the claim.

I claim:

A drafting triangle comprising a triangularly shaped flat body consising of relatively thin material and presenting at its margins a series of straight edges collectively defining a triangle, said body being provided With an opening located wholly within the margins of said body and there dening a plurality of inner edges, each one of References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 697,701 Ayer Apr. 15, 1902 1,519,646 Ward Dec. 16, 1924 1,579,137 Pecker Mar. 30, 1926 1,699,619 Muench Jan. 22, 1929 1,751,366 Shoub Mar. 18, 1930 2,536,401 Victor Jan. 2, 1951 FOREIGN PATENTS Number Country Date 133,588 Great Britain Oct. 16, 1919 

